[Abstract Title]. - Society for Neuroscience

Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 292.14/SS27
Topic: F.02.f. Fear and aversive learning and memory
Support: NSC96-2752-B-006-001-PAE
Title: A late expression of brain-derived neurotrophic factor in the amygdala is required for the
maintenance of long-term fear memory
Authors: L.-C. OU 1 , S.-H. YEH 2 , *P.-W. GEAN 2 ;
1 Inst. Basic Med. Sci., 2 Dept Pharmacol, Natl. Cheng-Kung Univ., Tainan 70101, Taiwan
Abstract: In many instances, increase in neuronal activity can elicit a biphasic secretion of a
modulator. The initial release of the modulator triggers the induction of synaptic plasticity
whereas the second phase reinforces the efficacy of synaptic transmission and the growth of
dendrites and axons. Here we show that fear conditioning induces a second peak of brain-derived
neurotrophic factor (BDNF) expression at 12 h post-conditioning. Fluorescent
immunohistostaining confirmed that BDNF expression was increased at 1 and 12 h after
conditioning and returned to baseline at 30 h after conditioning. Mature BDNF level was
similarly increased at 1 and 12 h after fear conditioning. Pre-training administration of TrkB IgG
or K252a impaired fear memory in a test carried out 1 day after training. By contrast, TrkB IgG
or K252a infusion at 9 h after fear conditioning, which did not affect memory retention measured
at 1 day after training, impaired memory when the rats were tested 7 days post-training. Fear
conditioning induced a significant increase in Zif268 expression in the amygdala 12 h after fear
training and the increase was completely blocked by TrkB-IgG infused 9 h post-training.
Growth-associated protein 43 (GAP-43), a marker of newly formed synapses, in the amygdala
was increased 7 days after fear conditioning. The change in GAP-43 was completely blocked by
pre-training or 9 h post-training infusion of TrkB-IgG. These results suggest that the second peak
of BDNF expression in the amygdala is responsible for the persistence of fear memory.
Disclosures: L. Ou, None; P. Gean , None; S. Yeh, None.
Poster
292. Acetylcholine, Neurotrophins, and Cognition
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 292.15/SS28
Topic: F.02.f. Fear and aversive learning and memory